This book constitutes revised selected papers from the 13th International Conference on Web Information Systems and Technologies, WEBIST 2017, held in Porto, Portugal, in April 2017. The purpose of the WEBIST series of conferences is to bring together researches, engineers and practitioners interested in technological advances and business applications of web-based information systems. The 12 full papers presented in this volume were carefully reviewed and selected from originally 77 paper submissions. They contribute to the understanding of relevant trends of current research on Web information systems and technologies, comprising unified interfaces, Progressive Web Apps (PWAs) as well as a mobile device taxonomy, XML and open data processing, the history of Web engineering, web development for end-users, access control, Web platform assessment, rule engines, and scientific blogging.